Ultimate Capacity of Drilled Displacement Piles: Static Analysis and CPT-Based Methods

Since the increasing use of drilled displacement piles in new constructions, estimation of their axial capacity has found great importance. This paper aims to analyze different predictive methods in projecting the ultimate load carrying capacity of drilled displacement piles. In this regard, two common approaches to determining the axial pile capacity based on static analysis and CPT-based methods are presented, compared, and evaluated. Also, a database is compiled and presented consisting of 69 drilled displacements pile load tests. Four different criteria were selected to evaluate the ratio of the predicted to measured pile capacities. To Compare the prediction of the pile's bearing capacity, estimation approaches, as well as their accuracy plus efficiency evaluation, the Rank Index (RI) was utilized. Based on this evaluation, method A, method B, and the American Petroleum Institute (API) method showed the best performance in predicting the ultimate load bearing capacity of drilled displacement piles.